const target = {}
const handler = {
    get:function(target,key){
        console.log('读取')
        return Reflect.get(target,key)
    },
    set:function(target,key,value){
        console.log('设置')
        Reflect.set(target,key,value)
    }
}
const proxy = new Proxy(target,handler)
proxy.age = 18
console.log(target,'target')